Left ventricular ejection fraction and heart failure: an indissoluble marriage?

Left ventricular ejection fraction (LVEF) is the most commonly used instrumental parameter to evaluate patients with heart failure (HF). The major strength of LVEF is that it is a universally known and accepted parameter, not only by cardiologists but also by all physicians. In addition, LVEF is relatively easy to obtain, as it can be determined using any cardiac imaging technique. A further advantage is that in clinical practice LVEF can be evaluated visually on echocardiographic images, which means rapidly, especially at a patient’s bedside or at home by means of portable echo scanners. Although all these features undoubtedly favour the use of LVEF in HF patients, there are also limitations. For example, LVEF does not correlate with patient symptoms, a normal LVEF does not exclude nor imply diastolic dysfunction, and LVEF cannot be used as a substitute for cardiac output. The aim of this article is to briefly review the role of LVEF in HF patients and then discuss a different view on how to categorize these patients instrumentally based on a pathophysiological approach.